This is a study of a cohort of 76,000 Navy personnel who worked aboard nuclear submarines from 1968-82. Radiation dose data along with detailed Naval job history will be obtained. Cancer mortality rates as related to the amount of radiation exposure will be determined. The association of respiratory and cardiovascular mortality will be examined in relation to duration and types of submarine experience as surrogate indices for the amount of exposure to air pollutants. The project statisticians will be able to utilize SAS on the GCRC Alpha Server DS 20 computer system.